User's Manual

Nortel Networks Confidential

Security and Administration

How this chapter is organized

This chapter is organized as follows:

• “Security strategy overview” on page 43

• “User administration” on page 45

Security strategy overview

One function of the RTP Media Portal is to secure the media interface

to the private network. Securing the media layer is achieved through a

combination of methods at the network level and RTP Media Portal

component level.

Network level security functions

At the network level, media layer security is achieved by the

randomization of the IP addresses/ports used for multimedia sessions

and utilization of NAPT (Network Address Port Translation) technology

to obscure the network topology of the private network.

Blade (IP address) randomization

When a multimedia session requests resources, the RTP Media Portal

selects an appropriate blade to host the session. Blade selection

determines the specific IP address that will be made available to the

media streams for the session.

During the selection of a blade, the port usage of each blade is queried

to determine the number of available ports for each. The blade which

has the most available ports is selected. This method of selection

provides randomization and helps distribute the session load across

the blades.

Port randomization

When the RTP Media Portal is deployed, each blade is assigned a pool

of ports with a specific number of ports in a specific range based on

configuration data (Number Ports, Min Port Value, Max Port Value,

respectively). For more information on these configuration properties,